Ingersoll Rand Air Angle Grinder, 4 Inch T27, 12000 RPM 1 HP

Description

Continuous weld dressing and heavy beveling burn out electric grinders when metallic dust cakes internal motor windings. The Ingersoll Rand Air Angle Grinder, 4 Inch tool spins Type 27 wheels at 12000 RPM with a full one-horsepower motor. It removes heavy stock fast, but starving this motor of adequate air volume causes the internal governor to stall.

The drive system combines an internal centrifugal speed governor with a high-torque vane motor housing four phenolic composite rotor vanes. A ductile iron motor cylinder withstands line scale contamination from plant air drops. Spiral bevel gears forged from case-hardened alloy steel transmit rotational torque with minimal gear lash and gear chatter. Double-sealed ball bearings support the output spindle against severe radial grinding loads, while a solid steel housing protects internal components from factory floor drops.

Hardware Performance Matrix

Heavy industrial weld preparation and structural metal fabrication demand governed spindle RPM and durable spiral bevel gear reduction. This four-inch pneumatic angle grinder removes thick weld beads, mill scale, and casting parting lines without motor overheating.

• 12000 free speed RPM governed motor prevents wheel overspeed while maintaining cutting velocity
• 1.0 horsepower pneumatic wet-end generates sustained rotational torque through heavy grinding cuts
• Hardened spiral bevel gear reduction transfers drive power smooth while cutting gear noise
• Heavy duty Type 27 wheel guard shields technician hands from flying sparks and wheel fragments
• Solid steel motor housing endures rough treatment and drops onto concrete shop floors
• 3/8-inch NPT air inlet port accepts high-flow couplers to prevent pneumatic line restriction
• Rear exhaust deflector routes motor oil mist and vented air away from the grinding path

Dyno Realities Air Telemetry

Dynamometer testing measures dynamic air consumption of 38 CFM at 90 PSI dynamic under full grinding stall, compared to 11 CFM at governed free-spin. Spindle speed drops from 12000 RPM down to 9400 RPM under aggressive grinding pressure on steel plate. Dynamic line pressure loss across 50 feet of 1/2-inch hose measures 6 PSI under continuous load. Adiabatic air expansion chills the rear exhaust to 28 degrees Fahrenheit. Operator ear sound testing records an acoustic output of 84 dBA at full load.

Field Trade-Offs Application Filter

Heavy steel construction absorbs grinding vibration, but six pounds of tool mass creates forearm fatigue during overhead structural weld work. Small automotive repair shops using three-horsepower piston compressors must avoid this grinder; inadequate air volume trips the speed governor, causing immediate motor stall and glazed grinding wheels.

• Inject six drops of ISO VG 32 pneumatic oil into the air inlet before each shift.
• Grease the spiral bevel gear set through the gear case port every forty operating hours.
• Inspect the Type 27 wheel guard clamp bolt for tightness before mounting fresh wheels.

Commercial Warranty Package Inventory

Ingersoll Rand backs this industrial M2 series grinder with a 1-Year limited commercial warranty covering drive motor and gear train defects. The unboxing package contains the four-inch pneumatic angle grinder, a Type 27 protective wheel guard, spindle mounting flanges, dual service wrenches, and an original manufacturer instruction manual.